3.91% is the change from 639 to 664
Calculation steps:
[( 664 - 639 ) ÷ 639] x 100 = 3.91%
Formula
Percentage change = [(664 - 639) / 639] x 100
Subtract the new number by the original number
664 - 639 = 25
25 ÷ 639 = 0.03912363067292645
0.03912363067292645 x 100 = 3.91%